TITLE:
Accuracy of self-reported medicines use compared to pharmaceutical claims data amongst a national sample of older Australian women
AUTHORS:
Xenia Dolja-Gore, Sabrina W. Pit, Lynne Parkinson, Anne Young, Julie Byles
KEYWORDS:
Medicines; Ageing; Agreement; Women; Self-Report; Pharmacy Records; Validation; Survey
JOURNAL NAME:
Open Journal of Epidemiology,
Vol.3 No.1,
February
19,
2013
ABSTRACT:
This study assessed agreement between two measures of medicine use, self-report by mail and pharmaceutical claims data, for a national sample (N = 4687) of older women aged 79 to84 in2005, from the Australian Longitudinal Study on Women’s Health. Medicines used for common chronic diseases in older people were selected, with pharmaceutical claims data retrieval periods of three and six months. For six month retrieval, Kappa’s ranged between 0.44 (nervous system medicines) and 0.94 (glucose lowering medicines). For three month retrieval, aspirin (Kappa: 0.35) and folic acid (Kappa = 0.48) had lowest agreement. Women were least able to accurately report use of nervous system medicines (sensitivity 80%). Specificity was consistently high across all classes, suggesting women could accurately report using a medicine. Pharmaceutical claims data can assist evaluation of judicious medicines use, changes to availability and uptake of medicines, and track medicine expenditure for chronic conditions. Over-the-counter medicines, medicines not covered by pharmaceutical subsidies and those used on an as needed basis may be best measured by self-report, as use may be underestimated using pharmaceutical claims data.